This invention relates to a heat pump unit that can be stored within a confined enclosure that does not have access to the exterior walls of the building and, in particular, to a heat pump unit that is suitable for use in a small building such as a mobile home or the like, where usable space is at a premium.
Bingham, in U.S. Pat. No. 4,598,558 describes a heat pump that can be mounted within a small building that does not require access to the exterior walls of the building. The heat pump in contained within a housing having upper and lower compartments. The upper compartment for handling outdoor air that contains an outdoor heat exchanger (herein referenced to as a coil), a blower, and a compressor. The lower compartment contains a second coil and blower and is adapted to handle comfort or indoor air that is being conditioned. The outdoor air is drawn from the attic of the building and is exhausted through the floor of the building into the cellar. Comfort air is drawn through a side wall of a room and is exhausted into a distribution duct located beneath the floor of the building.
Although the Bingham unit is configured to save space when compared to other free-standing heat pumps, the air path through the housing on the outdoor air side of the unit is tortuous and thus adversely affects the overall performance of the unit. In addition, the compressor, which is mounted in the upper compartment, generates a good deal of heat which can adversely effect performance when the unit is operating in a cooling mode.
Addington, in U.S. Pat. No. 5,271,242 discloses a unit that is very similar to the Bingham unit wherein the outdoor air components are stored in a lower compartment and the indoor air components are stored in an upper compartment. Here, outdoor air enters and leaves the unit through the bottom wall of the unit. In one embodiment, a single duct brings both outdoor air to and from the unit. In a second embodiment, two individual ducts situated beneath the floor of the building are required to service the lower compartment. Like Bingham, Addingham utilizes a good deal of space and because of its configuration forces the air moving through the unit to follow circuitous routes.
A primary concern relating to free-standing heat pumps that must be stored in a confined enclosure such as a closet, is the capability of gaining access to the various component for the purpose of servicing or maintaining the unit. Typically, the unit is enclosed within an integral housing which necessitates pulling the entire unit from the closet in order to gain access to all parts of the unit. This can be a time-consuming, difficult and costly task.